Pneumatic conveyor system with radioactive signal elements



Dec. 18,- 1962 G. H. CORK ETAL PNEUMATIC CONVEYOR SYSTEM WITH RADIOACTIVE SIGNAL ELEMENTS Original Filed Sept. I1, 1952 3 Sheets-Sheet 1 Dec. 18, 1962 G. H. CORK ETAL PNEUMATIC CONVEYOR SYSTEM WITH RADIOACTIVE SIGNAL ELEMENTS Original Filed Sept. 11, 1952 3 Sheets-Sheet 2 wvayroes Gonna/v H. CoRK WILLIAM J. HAFNER Korrs HRIDAN ATTORNEVS Dec. 18, 1962 G. H. CORK EFAL 3,069,111

PNEUMATIC CONVEYOR SYSTEM WITH RADIOACTIVE SIGNAL ELEMENTS Original Filed Sept. 11, 1952 3 Sheets-Sheet 3 11.25:.5 L I44 [WI [36 zz g X .11: I? 1 l I36 [Z6 INVENTORS Gonna/v H C on WILLIAM J. HAM/5R Korrswl/mmm A TTORNEVS Unite States Patent nice 3,069,111 Patented Dec. 18, 1962 3,069,111 PNEUMATIC GONVEYGR SYSTEM WITH RADIO- ACTIVE SIGNAL ELEMENTS Gordon H. Cork, Birmingham, Mich, and William J. llaiger, San .lose, Caiifi, said Hefner assignor to said or Original application Sept. 11, 1952, Ser. No. 309,114, now Patent No. 2,900,146, dated Aug. 18, 1959. Divided and this application June 3, 1959, Ser. No. 817,748

6 Claims. (Cl. 243-16) The present invention relates to improvements in a conveyor system. This application is directed to a system and structure utilizing radioactive signal elements, and is a division of patent application Serial No. 309,114, filed September 11, 1952, now Patent No. 2,900,146, in the names of William J. Hafner and Gordon H. Cork.

The invention deals generally to a conveyor system wherein a conveyor means passes a station. The conveyor means includes a radioactive signal element which is adapted to create a signal in a circuit when the conveyor means moves to a position adjacent the station. This signal operates an actuating means which performs a work function. The work function can be the operation of a paint spray gun, the selection of a path in a multiple conduit tubular conveyor, or a selected treatment of a workpiece, for example.

The invention is particularly described in connection with a pneumatic conduit system wherein a suitably addressed cylindrical message carrier is dispatched from any one of a number of stations or message centers and automatically conveyed through tubular conduits to a predetermined one of the other stations or centers.

The systems shown in the drawings embodies a plurality of fixed signal detectors which are arranged axially along a tubular conduit at each station or message center in accordance with a predetermined axial spacing pattern. A plurality of signal elements are positioned on the cylindrical message carrier and are adapted to be adjustably arranged thereon in accordance with the spacing pattern of the signal detectors at any desired station. When the signal elements of the carrier match the signal detectors at the desired station during the course of travel of the carrier, an electronic selector circuit is actuated to activate an electromagnetically operated diverter mechanism which directs the carrier to that station.

It is an object of the present invention to provide an improved conveyor system of the above type which achieves a greatly improved signal selectivity.

It is another object to provide such a conveyor system wherein a good pulse or signal can be obtained at very high or very slow speeds of the conveyor means.

It is a further object of the present invention to provide such a system and construction wherein much closer axial spacing of the signal elements is possible than heretofore.

It is another object of the present invention to provide such a system and structure wherein a more efficient and positive selector operation is achieved and a greater number of useful signal combinations is made possible.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

FIG. 1 is a digrammatic view of a portion of a message conveyor system showing a selector circuit embodying the present invention in use with a main conduit and a branch conduit.

FIG. 2 is an enlarged view taken in the direction of the arrows along the line 22 of FIG. 1.

FIG. 3 is a fragmentary diagrammatic view showing another selector circuit adapted to supplant the circuit shown in FIG. 1.

FIG. 4 is an enlarged view taken in the direction of the arrows along the line -4-4 of FIG. 3.

FIG. 5 is an enlarged side view of a carrier illustrating a modification of the signal mechanism.

FIG. 6 is a sectional view taken in the direction of the arrows along the line 66 of FIG. 5.

FIG. 7 is a fragmentary enlarged sectional view taken in the direction of the arrows along the line 7-7 of FIG. 5.

FIG. 8 is an end view of a message carrier, portions being broken away to illustrate a second modification of the signal mechanism.

FIG. 9 is a fragmentary sectional view taken in the direction of the arrows along the line 9-9 of FIG. 8.

FIG. 10 is a fragmentary sectional view taken in the direction of the arrows along the line 1010 of FIG. 9.

FIG. 11 is a fragmentary side view of a message carrier illustrating a third modification of the signal mechanism.

FIG. 12 is a fragmentary sectional view taken in the direction of the arrows along the line 12-12 of FIG. 11.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings,

- since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Details of a selector and diverter system for use with a main conduit and a branch conduit, and comprising a diverter mechanism and an electronic selector circuit, are illustrated in FIG. 1. A portion of a main tubular conduit 10 is connected by a Y-coupling 12 to a tubular branch conduit 14. The diverter mechanism of the system comprises a gate 16 pivotal at 18 to swing from an open position in parallelism with the conduit 10, FIG. 1, to a diverting position in parallelism with the conduit 14 at the location of its juncture with the conduit 10. The gate 16 is normally urged to the open position by means not shown and is operated by a lever 20 keyed to the gate at the pivot 18, so as to swing the gate leftward to the diverting position upon downward swinging of the lever 20. The latter is pivotally connected at 22 to the shiftable core 24 of a solenoid 26 and is swung downward about the pivot 18 in unison with downward movement of the core 24 when the solenoid 26 is energized. The diverter mechanism may be conventional if desired and is accordingly not described in further detail.

The electronic selector circuit of the system comprises a number of axially spaced signal detector rings 23, 31B, 32 and 34 arranged coaxially around the main conduit 10 adjacent and in advance of the coupling 12 with respect to the direction of travel indicated by the arrow. These detector rings are responsive to the energy emission from radioactive material and are adapted to receive radially directed signals from a corresponding number of radioactive cells adjustably spaced axially on the message carrier. Pulse forming circuits 36, 38, 40 and 42 are coupled respectively to amplification and shaping circuits 44, 46, 48 and 50 and with the screen and control grids 52, 54, 56 and 58 of a pair of thermionic gaseous discharge tubes or thyratrons 60 and 62. The plate circuit of-tube 60 extends in series through a relay coil 64, a normally closed relay shunt switch 66, low resistance shunt 68, limit switch 70, plate potential source 72, and cathode of tube 62. The plate of tube 62 is connected to the cathode of tube 60, so that the plate currents of the tubes 60 and 62 are in series. In consequence each tube 60 or 62 serves as an open switch for the other and neither tube can fire, i.e., conduct plate current, except in unison with firing of the other tube.

A negative bias on the screen and control grids 52 and 54 of tube 60 is indicated by the potential source 74 connecting the cathode of tube 60 with said. grids 52 and 54 through the circuits 44 and 46 respectively. Similarly a negative bias on the screen and control grids 56 and 58 of tube 62 is indicated by the potential source 7 6 connecting the cathode of tube 62 with said grids 56 and 58 through circuits 48 and 50 respectively. The negative bias on the grids 52 through 58 is determined so as to prevent firing of the associated tubes 60 and 62 until predetermined positive potential impulses are applied to the grids simultaneously, as for example from the circuits 44 through 50 respectively.

The circuits 36 through 42 are all the same, each having for its principal element a photomultiplier tube in an operative circuit. One of such tubes 78, which are well known to the art, is indicated schematically in FIG. 2 and comprises a coated cathode arranged to receive radiant energy from an external source and to emit a feeble electronic current to the first of a series of dynodes, whereupon the current is successively directed from dynode to dynode in the series and multiplied by secondary emission at successive dynodes. From the last dynode in the series, the highly amplified electronic current is directed through the anode of the tube to the amplification and shaping circuit as described in connection with FIG. 1. Since the photomultiplier tubes are amplifiers, it is apparent that these tubes may also be considered part of the amplification circuits. The necessity of subsequent amplification would depend upon the amplification factor of the tube and the initial radiant energy of the pulse originating signal.

In order to direct a signal from a radioactive cell on the cathode of the photomultiplier tube in each circuit 36 through 42, the transparent annular rings 28, 30, 32 and 34 are provided around the tube adjacent the photomultiplier tubes. The rings 28 through 34 are alike and comprise material having a high index of refraction, such as optical glass or one of the methyl methacrylate plastics for example known to the trade as Lucite or Plexiglas. Each ring 28 through 34 is also coated with a phosphor or suitable chemical, such as the coating 80 around the inner circumference of the ring 28, adapted to glow or luminesce when energized by radioactive emission.

A notch, such as the notch 82 formed in ring 28 con fronting tube 78 so as to direct light energy from within ring 28 to the cathode of tube 78 by the well-known edge lighting effect, is similarly formed in each ring 28 through 34. Accordingly when a radioactive cell on a message carrier passes through ring 28, radiant energy directed outward from the cell through the tube 10 will cause the coating 80 to luminesce. Light from the glowing coating 80 will enter the ring 28 and by virtue of the high index of refraction of the latter be conducted circumferentially by diffusion and refraction to the notch 82 and then to the cathode of tube 78, regardless of the portion of the ring 28 into which the emission from the radioactive cell is directed. In the above regard of course, the material of the conduit 10 at the region of the ring 28 is of steel or aluminum or other suitable material which is-not opaque to the radioactive emission.

Since the rings 30, 32 and 34 are coated and notched similarly to the ring 28 and arranged to direct light energy to the cathodes of the photomultiplier tubes of the associated circuits 38 through 42, a passing carrier provided with a suitable set of radially outward emitting radioactive cells spaced axially to match the axially spacing of the rings 28 through 34 will energize the photomultiplier tubes in the circuits 36 through 42 simultaneously. Signal pulses will thus be transmitted to all of the amplifying and shaping circuits simultaneously, the four grids of the tubes 60 and 62 will be raised to their firing potentials simultaneously, and the gate 16 will be shifted to the diverting position as above described. For any other axial spacing of the radioactive cells on the carrier which does not cause simultaneous stimulation for energizing of all four circuits 36 through 42, the gate 16 will remain in the open position of FIG. 1 and the carrier will not be diverted.

By the circuitry described, potential impulses induced in the rings 28 through 34 by radioactive signal means in detail.

It is apparent that when the predetermined impulses are momentarily induced simultaneously in the rings 28 through 34, the tubes 60 and 62 will fire, energizing relay coil 64, closing the normally open relay switch 88 and opening shunt switch 66. As a result, circuit through switch 88, potential source 60, and solenoid 26 is closed, energizing the latter to cause shifting of gate 16 to the diverting position as described above, whereupon a message carrier traveling along conduit 10 in the direction of the arrow will be diverted into the branch conduit 14. Immediately after being diverted irito branch conduit 14, the carrier will strike a limit switch operator 90 in the side wall of tube 14, thereby opening limit switch 70 to interrupt the plate circuit through tubes 60 and 62 and permit the latter to cease firing. Relay 64 will then be de-energized, permitting switches 88 and 66 to return to their normal conditions as indicated in FIG. 1. Opening of switch 88 will also de-energize solenoid 26, permitting the gate 16 to return to its normally open or non-diverting position, FIG. 1.

In the event that the signal means of a carrier passing the rings 28 through 34 are not adapted to induce the aforesaid predetermined impulses in all of the rings simultaneously, it is apparent that the tubes 60 and 62 cannot fire, the diverter mechanism will not be actuated, and the carrier will continue along conduit 10 and the coupling 12 without diversion. However, once the tubes 60 and 62 have been caused to fire, as for example by passage of a carrier having the necessary signal required to induce the aforesaid predetermined potential impulses in the rings 28 through 34 simultaneously, firing of the tubes 60 and 62 will continue until their plate circuit is interrupted, as for example by the opening of limit switch 70. Accordingly a resistance 92 is provided in parallel with shunt 68 to protect relay 64 from the full sustained plate potential across tubes 60 and 62. At the instant firing of tubes 60 and 62 commences. a sudden large potential is applied across relay 64 by virtue of shunt 68 which bypasses resistance 92 through normally closed switch 66. Relay 64 will thus respond rapidly to close normally open switch 88 and to open normally closed switch 66. Upon opening of the latter switch, the circuit through relay 64 is completed through protective resistance 92. During the short interval required for opening of switch 66 relay 64 is protected by its own high inductance.

Another pulse forming means responsive to radioactive emission is shown in FIGS. 3 and 4 wherein, in place of the rin s 28 through 34, annular Geiger tubes 94, 96. 98 and 100 are arranged co-axially around the conduit 10 in accordance with a predetermined axial spacing pattern and connected with suitable pulse forming circuits 102, 104, 106 and 168 respectively. Since the circuits 102 through 108 are alike in construction and operation and are similarly connected with their respective tubes 94 through 100, the circuit 102 for tube 94 only is shown in FIG. 4. Each Geiger tube comprises an outer electr cally conducting tubular shell or anode and an inner cathode, such as the annular cathode 110 of the tube 94. The interior of each tube 94 through 100 contains a suitable gas such as hydrogen under low pressure and adapted to break down or ionize when subjected to the emission from a radioactive source. The cathode and anode of tube 94 are connected through a potential source 112 and resistance 114 in the pulse forming circuit 102, whereby a potential drop across resistance 114 and consequent signal pulse in circuit 102 are effected upon ionization of the gas within the tube 94.

The other tubes 96 through 100 are similarly connected to their respective circuits 104 through 108. The circuits 102 through 108 are connected to the grids 52 through 58 respectively through amplification and shaping circuits comparable to the circuits 44 through 50 (FIG. 1) so as to raise the potentials of the grids 52 through 58 to the predetermined firing potentials in response to predetermined signal pulses from the circuits 102 through 103. Each tube 94 through 100 is constructed of suitable material adapted to transmit the emission from radioactive cells spaced axially on the carrier. Upon passage of a carrier having such cells spaced to match the axial spacing of the tubes 94 through 100, the predetermined signal pulse will be developed in each of the circuits 102 through 108 simultaneously, the tubes 60 and 62 will fire, and the gate 16 will be actuated to divert the carrier into the branch 14.

The systems illustrated in FIGS. 1 through 4 are highly efficient for use with either high or low speed carriers. A magnetic signal element would not operate at low speeds of the carrier. The efficiency of detecting the radioactive emissive type signal from the carrier is also increased by forming the conduit of suitable material such as aluminum or plastic which will not interfere and which is not opaque to the radioactive emission, although steel conduits are feasible with this type.

An example of a radioactive signal means is illustrated in FIGS. 5 through 7 wherein the outer wall of the carrier 116 is provided with an axial slot 118 opening into a number of axially spaced pairs of openings 120 of each pair extending circumferentially in opposite directions from the slot 118. The slot 118 and openings 120 are partitioned from the hollow interior of the carrier 116 by a base plate 122. Slidablealong the slot 118 are a number of vials or small containers 124 of lead or brass or other material adapted to contain a suitable radioactive material 126 and to prevent or minimize energy emission from each vial 124 except at the latters orifice 128 opening outward through the slot 118. As indicated in FIGS. 6 and 7, the interior sidewalls of the vial 124 converge outward toward the orifice 128 so as to direct the emission from the material 126 radially outward in a small diameter beam. The radially outer surface of the vial 124 is provided with ears or lugs 130 adapted to seat within the slots 120 and extends flush with the outer cylindrical surface of the carrier 116 when the lugs 130 are seated or located within the slots 120, FIGS. 6 and 7. Outer shoulder portions of the body of each vial 124" closely underlie the inner cylindrical surface of the carrier 116 adjacent the slots 120 when the lugs 130 are seated therein and are pressed outward by a spring 132 interposed between the base of the vial 124 and base plate 122. The spring 132 is formed of a strip of resilient sheet material having an outer end secured to the base of the associated vial 124 and an inner end flush with the base plate and slidable axially therealong, FIG. 7. Paired parallel guide plates 134 extend axially the length of the slot 118 adjacent the circumferentially spaced ends of the vials 124.

The signal means illustrated in FIGS. 5 through 7 is particularly adapted for use with the signal detection systems of FIGS. 1 and 2 or FIGS. 3 and 4. The axial spacing intervals between the corresponding signal detectors 28 through 34 or 94 through 100 are multiples of the axial distance between adjacent pairs of the slots 120. By spacing a number of vials 124 axially on the carrier 116 so as to match the spacing of the signal detectors 28 through 34 or 94 through at the station to which the carrier 116 is to be sent, all of the signal detectors associated with that station will be activated simultaneously by the radioactive emission from the several vials upon passage of the carrier 116. In consequence the carrier will be diverted into the immediately succeeding branch circuit as described above.

In order to index or adjust the vials 124 axially, the lugs 130 of the vial 124 to be adjusted are disengaged from the slots by depressing the vial inward against the spring 132, whereupon the vial is slidable axially of the carrier 116 to a desired adjusted position underlying another pair of slots 120. Upon release of the indexed or adjusted vial 124, the spring 132 will seat the lugs within the overlying slots 120, whereby the vial 124 is positively located at the indexed or adjusted position.

As indicated in FIGS. 8 through 12, instead of shifting the signal means axial-1y to achieve the various desired signal combinations, a number of the signal means are arranged on the carrier in an axially extending row and selectively shielded from the signal detectors or otherwise rendered ineffective in various desired signal combinations. In FIGS. 8 through- 10, a number of vials 136 generally similar to the vials 124 are arranged in a row between the side plates 134 and base plate 122. Each vial 136 contains radioactive material 126 and has a conical hollow interior converging to an orifice 128. In the present instance each vial 136 is pivotally supported between a pair of pins 138 spacing adjacent vials 136 and supported in turn by brackets 140 extending between the side plates 134. Keyed to each vial 136 coaxially with the pins 138 is a knurled disc 142 by which the vials are rotated, FIG. 9. Thus any vial can be rotated to direct its emission inward of the carrier and rendered ineffective as a signal means. By turning the orifice 128 of certain vials 136 inward and others outward so as to align with an axially extending slot 144 in the outer cylindrical wall of the carrier 116, various signal combinations are achieved to matchpredetermined spatial combinations of the radioactive signal detectors, such as the detectors 28 through 34 or 94 through 100 for example.

lnFIGS. l1 and 12, a number of vials 146, similar to the vials 124 and 136 and containing radioactive material 126, are arranged on the carrier 116 in an axially extending row similarly to the vials 136. In this instance, the vials 146 are secured immovab-ly between the side and base plates 134 and 122 respectively. The orifice 128 of each vial 146 is selectively covered by a shield148 which is opaque to the radioactive emission and which is pivoted to the outer end of the vial 146 by a pin 150, FIG. 12, so as to swing to and from a cover position, FIG. 11. Each cover 148 lies within an opening 152 in the outer cylindrical wall of the carrier 116 and is thus substantially flush with the latter, the opening 152 being also adapted to align with the vial orifice 128 when the latter is not closed by the swinging cover 148. The pivotal vials 136 may be frictionally retained in their adjusted positions or may be detained by suitable spring detent means.

Although the conveyor system has been specifically described relative to a message conveyor, it can be used with other devices as previously indicated.

For instance, a conveyor which takes diiierent parts past a paint spray booth could utilize the system. Radioactive elements can be set or adjusted on the conveyor so that the adjacent workpiece receives one of a number of possible paint sprays. The radioactive elements can be similar to those described in the drawing or may be constructed otherwise. Thus, as a predetermined signal is picked up by circuits similar to the circuits 3642 and 102-408 (FIGS. 1 and 3), a particular paint spray mechanism is actuated (in place of the gate 16) to perform the work function.

In a system such as just described, the speed of the conveyor and accompanying signal elements would be rela- Zr tively slow. A magnetic signal element would either give a slurred pulse or no pulse at all. However, applicants radioactive signal elements produce a good pulse with resultant efiicient operation of the actuating mechanism.

Having thus described our invention, we claim:

1. In a message conveyer system, a conduit having a branch conduit, a carrier adapted to travel along said conduit, signal means on said carrier comprising radioactive means arranged to direct its emission radially out- Ward at locations spaced axially of the carrier, electromagnetically actuated diverter means operative to divert said carrier from said conduit into said branch conduit, a plurality of signal detectors spaced axially of the conduit in advance of the branch conduit to receive said emission upon passage of said carrier, each detector comprising a generally annular member of transparent material around said conduit and having a sufficiently high index of refraction to conduct light circumferentially therein, a coating on each annular member of material adapted to convert a portion of said emission into visible light, said member having a notch therein for transmitting light from the interior of said member, photoelectric means associated with the notch of each member to receive light transmitted therefrom, and electromagnetic circuit means coupling each photoelectric means with said diverter means to operate the latter in response to a predetermined signal from said photoelectric means.

2. In a message conveyer system, a conduit having a branch conduit, 2. carrier adapted to travel along said conduit, signal means on said carrier comprising radioactive means arranged to direct its emission radially outward at locations spaced axially of the carrier, electromagnetically actuated diverter means operative to divert said carrier from said conduit into said branch conduit, a plurality of signal detectors spaced axially of the conduit in advance of the branch conduit to receive said emission upon passage of said carrier, each detector comprising a generally annular member of light conducting material around said conduit in advance of said branch conduit and having a sufliciently high index of refraction to conduit light circumferentially therein, a coating on each annular member of material adapted to fiuoresce when energized by said emission, each annular member having a notch therein respectively for transmitting light from the interior of said member, a pulse forming circuit associated with each annular member respectively and including a photomultiplier tube in each circuit respectively arranged to receive light transmitted from one of each of said notches, said pulse forming circuits being arranged to efiect electric signals responsive to light signals from said notches, and electromagnetic circuit means coupling said pulse forming circuits and diverter means to operate the latter in response to a predetermined electric signal from the former.

3. In a message conveyer system, a conduit having a branch conduit, a carrier adapted to travel along said conduit, signal means on said carrier comprising radioactive means arranged to direct its emission radially outward at locations spaced axially of the carrier, electromagnetically actuated diverter means operative to divert said carrier from said conduit into said branch conduit, a plurality of axially spaced annular Geiger tubes in pulse forming circuits operative to effect a predetermined electrical signal responsive to said emission upon passage of said carrier and arranged coaxially around said conduit in advance of said branch conduit, and electromagetic circuit means coupling said pulse forming circuits and diverter means to operate the latter in response to said signal.

4. In a conveyor system, a plurality of stations, each station including a plurality of spaced apart signal derectors, said signal detectors being spaced apart in ac cordance with a specific spacing pattern, a conveying means extending by said stations, a plurality of signalling structures for movement on said conveying means, each of said signalling structures including a plurality of spaced apart radioactive members, each of said radioactive members emitting radiant energy radially outwardly, saidradioactive members being spaced apart in accordance with a specific spacing pattern, electronically activated actuating means operative to perform a Work function associated with each station, said actuating means being activated by the signal detectors of the associated station when each of the signal detectors receives radiant energy from an adjacent radioactive member, said condition occurring when the signal detectors match, in number and spacing, the radioactive members of a signalling struc-- ture moving thereby on the conveying means.

5. In a message conveyor system, a plurality of stations, each station including a plurality of spaced apart signal detectors, said signal detectors being spaced apart in ae-- cordance with a specific spacing pattern, a main conduit extending by said stations, said main conduit having a plurality of branch conduits, a plurality of carriers adapted to travel along said main conduit, each of said carriers having a signalling structure, each of said signalling structures including a plurality of spaced apart radioactive members, each of said radioactive members emitting radiant energy radially outwardly, said radioactive members being spaced apart in accordance with a specific pattern, electromagnetically actuated diverter means associated with each branch conduit operative to divert said carriers from said main conduit into the associated branch conduit, said electromagnetically actuated diverter means being activated by the signal detectors of the associated stations when each of the signal detectors receives radiant energy from an adjacent radioactive member, said condition occurring when the signal detectors meet in number and spacing, the radioactive members of a carrier moving thereby in the main conduit.

6. in a message conveyor system, a plurality of stations, each station including a plurality of spaced apart signal detectors, said signal detectors being spaced apart in accordance with a specific spacing pattern, a main conduit extending by said stations, a plurality of carriers for travel along said main conduit, each of said carriers including a plurality of spaced apart radioactive members, each of said radioactive members emitting radiant energy radially outwardly, said radioactive members being spaced apart in accordance with a specific spacing pattern, said main conduit having a branch conduit for each station, electromagnetically actuated diverter means associated with each branch conduit and operative to divert a carrier from the main conduit onto the associated branch conduit, a plurality of pulse forming circuits associated with the signal detectors of each station, said signal detectors being responsive to the emission from the radioactive members of a passing carrier to effect an electric signal pulse in the associated pulse forming circuits, and electromagnetic circuit means coupling said pulse forming circuits and diverter means of a branch conduit to operate the latter in response to a predetermined signal pulse from tr e former, said predetermined signal pulse occurring when each of the associated signal detectors receives radiant energy from an adjacent radioactive member, said condition occurring when the signal detectors match, in number and spacing, the radioactive members of a carrier moving thereby in the main conduit.

References Cited in the file of this patent UNITED STATES PATENTS 1,797,864 Harlandt Mar. 24, 1931 1,983,342 Chambers Dec. 4, 1934 2,150,440 Hargreaves Mar. 14, 1939 2,323,128 Hare June 29, 1943 2,486,845 Herzog Nov. 1, 1949 2,707,555 Gaudin May 3, 1955 2,717,693 Holmes Sept. 13, 1955 

